This invention relates to fiber optic connectors and optical fiber systems.
Fiber optic connectors couple optical communication channels (e.g., optical fibers) to one or more optical devices (e.g., electro-optic and opto-electric devices). The optical communication channels may be defined by a bundle of glass or plastic fibers (a xe2x80x9cfiber optic cablexe2x80x9d), each of which is capable of transmitting data independently of the other fibers. Relative to traditional metal connections, optical fibers have a much greater bandwidth, they are less susceptible to interference, and they are much thinner and lighter. Because of these advantageous physical and data transmission properties, efforts have been made to integrate fiber optics into computer system designs. For example, in a local area network, fiber optics may be used to connect a plurality of local computers to each other and to centralized equipment, such as servers and printers. In this arrangement, each local computer has an optical transceiver for transmitting and receiving optical information. The optical transceiver may be mounted on a printed circuit board that supports one or more integrated circuits. Typically, each computer includes several printed circuit boards that are plugged into the sockets of a common backplane. The backplane may be active (i.e., it includes logic circuitry for performing computing functions) or it may be passive (i.e., it does not include any logic circuitry). An external network fiber optic cable may be connected to the optical transceiver through a fiber optic connector that is coupled to the backplane.
Other fiber optic applications have been proposed. For example, backplanes have been designed to interconnect the circuit boards of a computer system and thereby enable optical communication between the boards (see, e.g., U.S. Pat. Nos. 4,913,508, 5,134,679, and 5,793,919). These backplanes often are referred to as xe2x80x9coptical backplanes.xe2x80x9d Typically, an optical backplane includes one or more fiber optic cables that couple to connectors mounted on the edges of the printed circuit boards.
The invention features a fiber optic connector system that enables direct-board-to board optical communication that does not require data transmission through the backplane.
In one aspect, the invention features a fiber optic input. The input includes means for mounting the fiber optic input to a printed circuit board, an optical component, and an optical fiber receiving surface. The fiber-receiving surface has two or more alignment grooves configured to receive two or more optical fibers of a multi-fiber fiber optic cable and to guide the received fibers into optical contact with the optical component.
The optical component preferably includes two or more input optical fibers each disposed in a respective alignment groove. Non-contacting portions of the input optical fibers may be oriented at an oblique angle relative to the optical fiber receiving surface. The input may include a fiber guide configured to hold the input optical fibers and to align the input optical fibers with the alignment grooves of the optical fiber receiving surface. The input optical fibers preferably are unbound to the alignment grooves in which they are disposed. The alignment grooves may be each defined by a pair of adjacent side walls with widths that taper as they extend away from the optical fiber receiving surface.
In one embodiment, the optical fiber input includes a socket configured to receive a plug of a multi-fiber fiber optical cable. The socket preferably comprises an alignment rail for guiding the plug into alignment with the optical fiber receiving surface. The alignment rail may be configured to guide the plug so that optical fibers of the multi-fiber fiber optic cable are oriented at an oblique angle relative to the optical fiber receiving surface.
In another aspect, the invention features a fiber optic plug. The plug includes a body configured to hold two or more optical fibers, a cap having a front face through which the optical fibers are extendable, and a biasing member coupled between the body and cap.
The plug body preferably has a bore configured to receive a multi-fiber fiber optic cable. The plug body preferably is configured to hold the optical fibers in a spaced-apart, substantially planar array.
In one embodiment, the front face defines a plurality of spaced-apart openings through which the optical fibers are extendable. The front face openings preferably are configured to align the optical fibers with alignment grooves in a plug socket. The fiber optic plug may include a slot configured to slide along an alignment rail in the plug socket and thereby guide the optical fibers into alignment with the alignment grooves.
The biasing member preferably comprises a spring that is configured to urge the body and cap apart.
The fiber optic plug may be characterized by a retracted configuration in which the optical fibers are contained within a cavity defined by the cap, and an extended configuration in which the optical fibers extend through the front face of the cap. The fiber optic plug may include a locking mechanism configured to lock the cap to the body in the extended configuration. The locking mechanism preferably comprises a latch secured to the body and a hub secured to the cap.
In another aspect, the invention features a fiber optic connector system that includes the above-mentioned fiber optic input and the above-mentioned fiber optic plug.
Among the advantages of the invention are the following. The invention provides fiber optic connector system that enables direct board-to-board optical communication without the complexity and possible communication delays that would be required if data transmissions had to go through the backplane. The inventive plug and socket system enable the optical fibers of a multi-fiber fiber optic cable to be readily aligned and coupled to an optical device. In addition, the inventive fiber optic connector system may be installed and removed quickly and easily. Furthermore, the invention may be retrofitted into existing computer systems without difficulty.